Tack.



A. HAMILL.

TACK.

APPLIOATION IILBD FEB. 24, 1913.

Patented Feb. 17, 1914.

ALEXANDER HAMILL, 0F BALTIMORE, MARYLAND.

TACK.

Specification of Letters Patent.

Patented Feb. 1'1 1914.-

Application filed February 24, 1913. Serial No. 750,401.

To all whom. it may concern:

Be it known that I, ALEXANDER HAMILL, acitizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Tacks-z and I do declare the following to be a full, clear, and exact description of the. invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in sheet metal tacks or roofing nails adapted to be constructed in different sizes for various purposes.

The object of the invent-ion isto provide a simply constructed and efiicient tack of this character the blank of which may be struck out from a sheet of metal in a single operation.

Another object is to provide a tack of this class the shank of which is constructed to render it rigid and strong to add t it to withstand the force necessary to rive it into the object into which it is to be inserted.

A further object is to provide a tack of this class the head of which is convexed on its outer face by the angling of the shank and which is provided with converging article pressure fingers.

Vith these and other objects in view, the invention consists of certain novel features of construction and the combination and arrangement of parts as will be more fully described and claimed.

In the accompanying drawiilgs: Figure 1 is a perspective view of this improved tack; Fig. 2 is a side elevation thereof; Fig. 3 is a vertical section taken at right angles to Fig. 2: Fig. 4c is a bottom plan view of the tack; Fig. 5 is a similar view' of the blank from which the tack is formed; Figf 6 is a front view of a portion of the prong showing the spurs thereof deflected.

In the embodiment illustrated this improved nail or tack is constructed from a single blank sheet of metal as shown clearly in Fig. 5 and comprises a circular head or body portion 1 provided with a single prong or shank 2 formed by stamping a V-shaped member from said disk or head beginning with a point at the edge or periphery of said disk and gradually broadening toward. the base of said prong. The base of the prong extends beyond the center of the head and is bent at right angles to the head and then folded longitudinally to render it strong and Fig. 1.

rigid and adapt it to withstand blows from a hammer when necessary for forcing the shank or prong into the roof or other object .into which it is to be driven. The flanges 8 and 4 formed by the folding or bending longitudinally of the prong taper toward the free end of the prong forming a needle point to said prong to facilitate its insertion into an object, which is especially desirable when thedevice is in the form of a thumb tack.

The prong 2 is preferably notched at opposite sides thereof to form spurs 5 and 6 to prevent the accidental withdrawal 'of the tack after it has been inserted. In forming these notches during the stamping operation tongues 7 and 8 are produced on the head at opposite sides of the slot which is formed by the striking out of the prong and these tongue may remain or be cut off as desired. Thesespurs 5 and 6 may be arranged in alinement with the flanges 3 and 4- as shown' in Fig. 2 or they may be deflected as shown in Fig. 6 ifpreferred. The triangular slot or recess 9 formed by the striking. out of the prong extends. through one edge of the head and provides resilient gripping fingers 10 and 11 which are drawn toward each other by the longitudinal folding of the prong thereby producing a convexed shape to the 35 outer face of the head as shown clearly in The free ends of these fingers 10 and 11 are bent upwardly as shown at 12 toprevent them from puncturing the article into which the tack is driven and to provide curved lower bearing faces for yieldingly engaging the face of the article into which the tack is driven andjcausing said tack head I to snugly engage said article.

The prong 2 extends beyond the center of 95 the disk or head to adapt it to be made of greater length than the radius of said'bead, long shanks being oftendesirable for tacks of this character especially for those used. for securing roofing papers and building linings. v

I While I have described my invention-with more or less minuteness as regards details and as being embodied in certain precise forms, I do not desire to be limited thereto unduly any more than is pointed out in the claims. On the contrary, I- contemplate all proper changes in form, construction and arrangement, the omission of immaterial elements and substitution of equivalents as 110 circumstances may suggest or render expedient.

1 the edge of the metal s eet broadening toward its base forming a slot .thereof, said prong I claim asmy invention:

1. A tack composed of a single piece of sheet metal havin a prong struck out therefrom, said prong eing bent at right-angles 5 thereto and folded longitudinally throughi5 na 1y.

3. A tack composed of a single piece of sheet metal having a prong struck out from said sheet through one edge thereof forming yieldable gripping fingers having their ends upturned.

4.. A tack composed of a sheet metal disk slit from its interior through its edge to form a tapered prong with its pointextending outwardly, said prong being bent at right-angles to said disk.

5. A tack composed of a sheet metal disk having slits extending from a point near its center through its periphery, said slits converging toward the peri hery of said disk to form a tapered prong disposed near the center of said disk, said pron being bent at right-angles to said disk and olded lon 'tudinally, the fold decreasing in depth rom the point of the prong inward, said disk having its outer face convexed and provided with gripping fingers extending outward.

6. A tack comprising a shlaet metal head having slits extending from its periphery inward and diverging toward their inner ends forming a triangular tongue, said tongue being folded longitudinally and bent at rlght ang es to said headto form a shank, said head aving the points at its periphery formed by said slits bent laterally in a direction opposite to said shank.

In testimony whereof l have hereunto set m hand in presence of two subscribing witnesses.

. ALEXANDER HAMIlJL.

Witnesses:

L. O. HILTON, M. H. STUARD.

aving a wide base 

